DOE OSTI2022
Capturing carbon dioxide (CO 2 ) and placing it in permanent storage in geologic formations is an option for reducing CO 2 emissions, but it may not be a viable one for all CO 2 emitters. For some, the added cost of capture may be too high to implement, or the geology near the source may not be suitable for storage. In these circumstances, other options will be needed. Carbon use and reuse, or CO 2 utilization (CO2U), is an alternative approach that seeks beneficial uses for captured CO 2 , such as using it as a feedstock in the production of fuels, chemicals, and building materials. These uses would give CO 2 value that could be used by suppliers (emitters) to offset capture costs. One of the principal features and challenges associated with CO2U is that the products derived from CO 2 must have lower carbon footprints than their conventional counterparts. Previous assessments of CO2U alternatives have focused on the carbon content of utilization products as an indicator of CO 2 equivalent (CO 2 e) emissions reduction potential. However, embodied emissions are—at best—only weakly correlated with the amount of carbon contained in any physical product. Therefore, the most attractive CO2U options will both displace the carbon in an existing product and improve the overall carbon efficiency of the manufacturing process. Research to overcome barriers will include identifying existing co-feeds and available low-carbon energy sources to enable the conversion of CO 2 to value-added products under favorable processing conditions. New discoveries in the fields of nano- and bio-technology will be applied to efficiently utilize CO 2 in new applications. Development of advanced materials and processes, integrating CO 2 capture with utilization processes (e.g., algae), exploring a diverse slate of products from CO 2 to effectively offset capture costs and developing processes based on waste energy are means to overcome these barriers. The research will lead to the development of advanced catalysts, materials, and equipment that can be used to convert CO 2 into useful products. The result will be multiple flexible and adaptable technology platforms that can be used to produce suites of products spanning multiple utilization pathways.
54 ENVIRONMENTAL SCIENCES↗